What Are Hard Structures?
- A jetty is built perpendicular to the shore, usually at inlets, and extends out into the water. It blocks the current moving down the beach, called the longshore drift, and holds sand in place and prevents the end of the island from washing away and the channel through the inlet from filling with sand. Typically, jetties are concrete or rock structures built at inlets and channels in order to maintain channels for shipping and navigation.
- A groin is built perpendicular to the coast and works similar to the way a jetty works. But groins are usually smaller than jetties and built on straight stretches of beach, not near inlets or channels. They are often built in a series of parallel structures on one section of beach and can be made of wood, concrete, steel or stone. Terminal groins are relatively new concoctions. They are the name proponents have given to small jetties built at inlets — the terminus of islands.
- A sea wall, as the name suggests, is a wall built along the coast between the land and the ocean. Sea walls are typically made of concrete or stone and can be very large structures.
Why Are Hard Structures Bad?
While they can protect roads, beach homes and other buildings threatened by erosion, hard structures usually cause increased erosion further down the beach. Both jetties and groins, for example, act like dams to physically stop the movement of sand. They work by preventing longshore drift from washing sediment down the coast. As a result, they cause a buildup of sand on the side protected by the structure — which is precisely what they’re intended to do. But areas further “downstream” on the coast are cut off from natural longshore drift by these barrier-like structures. No longer replenished by the sand that usually feeds them, these areas experience worsened erosion.
Don’t be confused and beguiled by proponents’ claim that groins are needed to “preserve” the beach. Without them, says this line of perverse reasoning, the beach would erode away and the public access would be restricted. Erosion is natural. Every sandy beach in the world is being whittled away by waves and wind. If left on its own, the beach retreats in the face of this constant onslaught. It will always be there, but maybe not in the same place or in the same form. Erosion is only a problem when we put buildings and roads in the way. Then it must be stopped with things like groins. So a groin’s only purpose is to hold the beach in place to protect the property behind it. If a legislator uses this line of reasoning to justify groins, gently ask why he/she isn’t considering allowing them at Cape Lookout, Portsmouth Island or Bear Island. All have higher erosion rates than Bogue Banks, Holden Beach or Figure Eight Island and all are popular tourist destinations. Certainly, if the beach needs to be preserved for the public’s use, those places should have priority. The answer, of course, is there are no houses or roads on those preserved beaches. So no need for groins.
History of the “Seawall” Ban
Historically, North Carolina has tried to avoid the problems than can be brought on by the use of hard structures to control erosion. In 1985, the North Carolina Coastal Resources Commission (CRC), a policy-making body for the coastal management program, studied the effects of hard structures on beaches in other states. The CRC concluded that the potential negative effects of such structures could cause irreversible damage to North Carolina’s beaches. As a result, the CRC recommended banning the construction of hard structures to protect buildings at the coast. The ban made exceptions for protecting historic buildings that could not be moved and for maintaining important waterways needed for navigation, such as Oregon Inlet in Dare County.
The regulatory ban on hard structure existed in practice for 15 years before it was upheld in court in a 2000 case. In 2003, the North Carolina General Assembly voted unanimously to formally adopt the hard structures ban as law. The law banned the construction of most new, permanent erosion control structures on the beach but contained the same exceptions as the regulatory ban.
The state’s environmental community has consistently supported this prohibition on these hard structures.
Attempts to Repeal the Ban
A number of beach communities, led by Figure Eight Island, have long lobbied for an exception to the legislative ban to allow “terminal groins.” They were trying to sell the notion that these small jetties at the end of island will control erosion and reduce beach re-nourishment costs. They also claim that these structures are somehow benign and won’t lead to accelerated erosion farther down the beach.
The North Carolina Senate passed a bill in 2008 to allow “terminal groins” but it went nowhere in the North Carolina House.
Coastal Resources Commission Study
In an attempt to break the logjam, the legislature ordered the Coastal Resources Commission to conduct a study on “terminal groins.” The commission hired engineering consultants, who could find no scientific evidence that terminal groins won’t harm beaches. The study also confirmed that groins won’t eliminate the need for costly beach re-nourishment.
Based on those findings the commission found no compelling reason to recommend that the ban be changed. But neither did the commission vote to uphold the ban. Recognizing the subject’s political volatility, it instead recommended that the legislature attach environmental and fiscal conditions to any bill that allowed groins. The legislature looked to the CRC for guidance but got a muddled response instead.
Repeal of the Ban
In 2011 by passing the Senate Bill 110 the North Carolina General Assembly repealed a 30-year-old ban on hardened structures and allowed up to four “test” terminal groins to be built in North Carolina. Four permit applications for construction of a terminal groin have been submitted to the federal U.S. Army Corps of Engineers’ district office: Figure Eight Island, Ocean Isle Beach, Holden Beach and Bald Head Island. Only Bald Head Island has acquired a permit from the Corps and the first phase of their terminal groin is complete. The other three projects are currently in the permitting process with the Corps of Engineers and are subject to further regulatory and public review and comment. In the 2015 session of the General Assembly the legislators passed a bill that will allow two more terminal groin projects to apply for the required permits. North Topsail Beach and Emerald Isle are the two municipalities that are considering proposals for these new potential additions to hardened structures on our public beaches.